This invention relates to an alterable mode-oscillator and more particularly to a precision oscillator capable of generating in one mode a triangular wave and in another mode a sawtooth wave. Both kinds of voltage waveforms are used in a variety of circuits, e.g., in pulse width modulators, with voltage controlled oscillators for generating distinctive audible alarm signals, and in circuits for cathode ray tube scanning, etc.
It is known to charge a capacitor in an oscillator from a current source. Such an oscillator is described in my patent U.S. Pat. No. 4,147,996 issued Apr. 3, 1979 assigned to the same assignee as is the present invention.
It is an object of the present invention to provide a precision oscillator that is capable of operating in a triangle waveform mode and a sawtooth waveform mode.
It is a further object of this invention to provide such an oscillator having an integrated circuit portion and a discrete capacitor, wherein a switched constant current source periodically and alternately charges and discharges the capacitor when operating in the triangle waveform mode.